Core for forming concrete conduits



July 2, 1940. w. j. LALLY CORE FR FORMING CONCRETE CONDUITS Filed Nov.17. 19?7 2 Sheets-Sheet 1 /NVENTOR W. J. ALLY er ATTORNEY July 2, 1940.w. J. LALLY CORE 'OR FORMING CONCRETE CONDUITS Filed Nov. 17, 1937 2Sheets-Sheet 2 ATTORNEY Patented July 2, 194() UNITED STATES PATENToFFicE CORE FOR FORMING CONCRETE CONDUITS Application Nsvember 17, 1937,serial No. 175,000

2 Claims.

This invention relates to a method of casting concrete or othercementitious conduit, and more particularly to a collapsible form orcore for joining and making bends in conduit.

The object of the present invention is the provision of a core or formfor making concrete joints in conduit which will readily adapt itself tothe size and shape of the conduit to be joined.

Another object of the invention is the provision of a core or form formaking conduit joints which may be readily removed after the concrete orother cementitious material has .hardened.

A still further object of the invention is the provision of a form orcore for making joints in conduit, which may be curved to form bends ofdifferent radii.

In accordance with the preferred form of this invention, there isprovided a iiexible, distensib-le and collapsible form or core forforming cementitious or concrete joints in conduits and the like. Thisform or core is constructed from rubber or some other suitable material,which is readily expansible, and comprises an elongated tube closed ateach end and having means therein for the introduction and release offluid pressure. The walls of said form or core, at each end, aresomewhat thinner than the middle or intermediate portion of the form,said thinwall portion extending some distance from each end thereof. Dueto the form having thin wall end portions it will, when pressure isintroduced therein, expand and will cause the ends of the forni toconform to the inside contour of the end of the conduits to be joined.In other words, if the bore of the one conduit is circular, the end ofthe form or core will assume a round shape and if the bore is square, itwill assume a square configuration.

This and other features of the invention will be more fuuy brought outin the foiiowing description when read in connection with the followingdrawings of which:

Fig. 1 is a foreshortened plan view of the core or form in its deflatedcondition;

Fig, 2 is an enlarged fragmentary view partly` in section whichillustrates the unequal wall thickness of the tube and also the airvalve and its operating mechanism;

Fig. 3 is a longitudinal sectional view of two fragments of conduit withthe core or form inated, the ends thereof distended and embracing thewalls of the conduit;

Fig. 4 is an enlarged fragmentary sectional engagement with theextending view of the end of a conduit with the core therein andconcrete therearound; and

Fig. 5 is a fragmentary perspective view partly in section showing aportion of a six-way conduit in position with two branches leadingtherefrom, said branches formed in the concrete by means of the core orform shown in Fig. 1 and a pipe section attached thereto.

Referring now to the drawings, the form or core member l0 is constructedof rub-ber, or

the washer I6 bears against the outer surface,

but has interposed therebetween a portion of the end of the tube l0, andas shown in Fig. 2k this bent-over portion of the tube l0 serves as agasket when the two washers I0 and Il are drawn toward each other bymeans of the U- shaped bracket I8 which threadedly engages and issecured to the outer surface of the valve stern I9, which in turn yis inthreaded engagement with the inner washer ll, thus forming an airtightjoint.

Inside of the Valve stem I9 is a valve mechanism 2U (which is of thewell-known bicycle tire type). This valve serves as a means for inilatngand deflating the tube l0. As shown in Fig. 2, there is associated withthe valve mechanism 20 and pivotally mounted on the U-shaped bracket I8,a mechanism for remotely controlling the deiiation of the core i0. Thismechanism comprises a link member 2l pivoted at `22 on the U-shapedbracket I8. A cam 23 is pivotally mounted thereon and is adapted toengage the extending portion 24 of the valve mechanism 20 when the linkarm 25 rotates on its pivot 26 and is moved upward in the position, asshown in the dot-and-dash lines in Fig. 2, when tension is applied onthe rope 21. The spring 28 tends to hold the link arm 25 down in itsnormal position, as shown by the full lines in Fig. 2, therebymaintaining the cam 23 in a position out of portion 24 of the valvemechanism 20.

By referring to Figs. 1 and 2, it will be observed that a valvemechanism and release therefor, such as described above, is located ateach` end of the tube l and that after the tube I0 is deflated, by meansof the operation of the valvereleasing device, it may be removed byfurther tension on the rope 21. l

As shown in Fig. 3, the tube I0 has been inflated and is positioned inthe bores 28 and 29 of the conduit 30 and 3| with the inated ends Il andl2 firmly embraced by the walls 32 and 33 and sealing the ends of thebores 28 and 29 to prevent the entrance of cementitious material. sureinto the tube I0 is secured to the valve at the Vend Il. This hose isthreaded through the bores of the conduits together with the rope 21.

Operation this invention, the ends Il and l2 of the tube I0 are insertedin the ends of the conduit or pipe to be jointed. Fluid pressure isintroduced through the hose 34, Which in turn causes the ends Il and l2to distend due to the thin wall section, While the diameter of theintermediate portion I3 of the tube lll increases slightly. Theexpansion of the ends Il and l2 causes the tube I0 to firmly embrace theWalls of the conduit or pipe and forms a tight seal. The concrete orother cementitious material is then introduced around the tube Il] andfirmly encloses the ends of the conduit or pipe and the tube l0. Afterthe concrete has hardened, the air is released from the tube I0 by meansof the valve actuating mechanism shown in Fig. 2, which is operated bymeans of the rope 21. After the air has been released, the tube l0 willdeflate and assume the shape as shown in Fig. 1, whereby it may beeasily removed from the concrete inasmuch as the diameter of the tube I0is noW slightly less than the bore in the concrete. The removal of thetube l0 is accomplished by applying tension to the rope 21, asheretofore described.

In order to illustrate another use for the inven- A hose 34 for theintroduction of fluid pres-Y tion, I have shown ln Fig. the joining ofsingle bore round conduit or pipe to the square bore of the multipleduct conduit. As shown in this figure, the tubes or forms 35 and 36 areinflated and their ends 31 and 38 are firmly embraced by the squarebores 39 and 4D of the conduit 4l, while the other ends 42 and 43 arefirmly embraced by the bores of the pipes or conduits 44 and 45. Theconcrete or other cementitious material 46 completely surrounds andencloses .the ends of the pipes 44 and 45, the conduits 4| and 41 andthe tubes or forms 35 and 36. After the concrete has hardened, the coresor tubes 35 and 36 are removed, as heretofore described.

'Ihe core or form of app-licants invention is simple and relativelyinexpensive to manufacture and due to its novel construction adaptsitself to various sizes and shapes of openings or bores and may be veryreadily removed from the completed joint.

It is to be understood that the invention is not limited to the detailsshown as various changes and modifications may be made Without departingfrom the spirit of the invention and it is only limited by the scope ofthe appended claims.

What is claimed is:

1. A form for making joints in conduits and the like, comprising asingle piece of expansible material molded to provide an inflatable formhaving Walls of non-uniform thickness, the Walls at each end of the formbeingy comparatively thin and the intermediate portion being relativelythicker. l

2. A form for making joints in conduits and the like, comprising asingle piece of expansible material molded to provide an inflatable formhaving walls of non-uniform thickness, said Walls at each end of theform being comparatively thinner than the intermediate portion thereof,and a valve mechanism at each end of said form for the introduction andrelease of uid pressure.

WILLIAM J. LALLY.

